(004/CEden) Ceratophysella denticulata (Bagnall, 1941)

*distinguenda (Bagnall, 1941)

Ceratophysella denticulata is a very common and widespread species found in damp habitats, especially those rich in organic matter. Records for Ceratophysella 'armata' are probably mostly of this species. The 'denticulata group' contains Ceratophysella with seta p1<p2 on abd4 (Fig. 7). 

Ceratophysella denticulata is identical with Ceratophysella engadinensis except for the presence of 3+3 a setae between the p3 sensilla on abd5 (a'2 present - see Fig. 8); Ceratophysella engadinensis has only 2+2 a setae between the p3 sensilla on abd5 (a'2 absent). Both species have seven setae on the dens (Fig. 3). There are no confirmed records for the very similar Ceratophysella succinea which has only six setae on the dens.

Map of Ceratophysella denticulata, updated June 2013

Eye of Ceratophysella denticulata

Figure 1: Eye of Ceratophysella denticulata collected from Swanley, Kent in May 1950. There are eight ocelli (A-H).

Eye of Ceratophysella denticulata showing post-antennal organ

Figure 2: Same field of view as Fig. 1 with slightly different level of focus showing post-antennal organ (PAO).

Furca of Ceratophysella denticulata

Figure 3: Furca of Ceratophysella denticulata collected from Woodbastwick, Norfolk in October 1955 by Theresa Clay. The dorsal side of the dens bears seven setae (1-7).

Anal spines of Ceratophysella denticulata

Figure 5: Anal spines of the same specimen at the same magnification.

Foot of leg2 of Ceratophysella denticulata

Figure 4: Foot of leg2 of Ceratophysella denticulata collected from Woodbastwick, Norfolk in October 1955 by Theresa Clay; emp, empodium with basal lamella.

Posterior abdomen of Ceratophysella denticulata

Figure 6: Posterior abdomen of Ceratophysella denticulata collected from Lightwater, Surrey in May 1951. Higher magnification views of abdomen 4 (white box) and abdomen 5 (green box) are shown in Figs. 7 and 8 respectively.

Dorsal chaetotaxy of fourth abdominal segment of Ceratophysella denticulata

Figure 7: Dorsal chaetotaxy of fourth abdominal segment of the specimen shown in Fig. 6. Seta p2 (reflexed forward by pressure from the cover slip) is much longer than p1. There are 3+3 axial setae (a1, m1 and p1) between the p2 macrosetae (cf. 2+2 in Ceratophysella gibbosa).

Dorsal chaetotaxy of fifth abdominal segment of Ceratophysella denticulata

Figure 8: Dorsal chaetotaxy of fifth abdominal segment of the specimen shown in Fig. 6. Note the presence of seta a2' (absent in Ceratophysella engadinensis). This individual shows asymmetry; on the right hand side, seta a2 is shifted posteriorly in comparison to the same seta on the left. (M (macroseta) = p1; s (sensilla) = p3)

 
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